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keto tuna casserole with zucchini noodles in white casserole dish

Keto Green Chile Tuna Casserole (with zucchini noodles )

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4.7 from 27 reviews

  • Author: Lindsay Cotter
  • Total Time: 45
  • Yield: 6 1x


This keto tuna casserole has zucchini noodles and green chiles for a delicious paleo, low-carb, high protein meal. Make this easy spiralizer recipe; it’s just like mom’s tuna noodle casserole, but MUCH healthier!


Units Scale
  • 56 cups spiralized noodles or 3-4 large zucchini (see notes for prep)
  • 1215 ounces canned tuna or 2 1/2-3 cans, drained
  • 1/2 cup real mayo (add 1/4 cup more for extra creaminess)
  • 4 ounces diced green chiles
  • 2 Tablespoons chopped chives + extra for topping
  • 1 Tablespoon organic regular or spicy mustard
  • 1/2 teaspoon seasoning salt
  • 1/4 teaspoon garlic powder
  • 1/4 teaspoon black pepper
  • 1 Tablespoon olive oil
  • 1/2 cup chopped onion
  • 1/2 cup chopped celery or green peas
  • 1/2 teaspoon chili powder or red pepper flakes
  • 2 Tablespoons coconut flour or tapioca starch (see notes)
  • 1/2 cup almond milk or coconut milk
  • Garnish – herbs (fresh parsley or cilantro) and optional fresh lemon slices


  1. Preheat oven to 350 F. Spray a 9×13 casserole dish with nonstick cooking spray. Set aside.
  2. Ribbon cut or spiralize the zucchini into noodles. Press/squeeze out as much excess water as possible (see notes). Set aside.
  3. In a large bowl, mix together the drained tuna, mayo, green chiles, chives, mustard, seasoning salt, garlic powder and black pepper. Set aside.
  4. Heat a large skillet on medium heat. Add the onion, celery and chili powder. Sauté 5 minutes or until onions begin to brown.
  5. Whisk coconut flour and milk into the celery and onion mixture until smooth or very few flour clumps remain. 
  6. Add zucchini noodles to the skillet and toss together. Cover and cook for 1-2 minutes on medium heat until zucchini is softened but not thoroughly cooked. 
  7. Remove skillet from the heat and pour contents into the tuna/green chiles mixture combining well.
  8. Pour mixture into the prepared casserole dish and bake for 15-20 minutes or until edges are browned. Optional- broil casserole 1-2 minutes for crispier edges.
  9. Garnish with fresh herbs and top with optional lemon slices.


Zucchini Noodles – Press out ALL water from tuna and zucchini before mixing together or the casserole will have too much liquid. Reader Tip from Missy- Place the zucchini noodles on a baking sheet and bake at 250F for 20-30min (depending on the thickness) to “dry” out the noodles.

Storage Tip – This casserole can be frozen for up to 3 months. It will have extra water once thawed due to the zucchini. Simply mix in more flour.

Substitute – Arrowroot starch can be substituted for the coconut flour or tapioca starch.

  • Prep Time: 20 min
  • Cook Time: 15 -20 min
  • Category: dinner
  • Method: baking
  • Cuisine: American


  • Serving Size: 1
  • Calories: 209
  • Sugar: 3.3g
  • Sodium: 507mg
  • Fat: 16.1g
  • Saturated Fat: 0.2g
  • Carbohydrates: 6.6g
  • Fiber: 2.4g
  • Protein: 10.3g
  • Cholesterol: 22.6mg